106 Dr. Henry Sicks — The Age of the Morte Slates. 



Silurian age of the Morte Slates to be so well established that it 

 may be accepted as the basis for future work." Clearly this was 

 too much for Dr. Gregory, and his righteous indignation compelled 

 him at once to endeavour to put a stop to any such assumption. 

 I do not, however, think that I shall have much difficulty in 

 showing that Dr. Gregory's facts and conclusions are unreliable, and 

 show a want of care and discrimination. Whether the fossils turned 

 out to be Silurian or Lower Devonian, would have mattered but 

 little in regard to my views of the stratigraphical position of 

 the Morte Slates ; for what I maintained from the first was, that 

 the Morte Slates, instead of being newer than the Ilfracombe beds 

 (Middle Devonian), were older than the latter, and that the apparent 

 upward succession was a deceptive one, and had been produced 

 mainly by thrust faults. If, therefore. Lower Devonian beds 

 occurred in the Morte ridge, the evidence would have been quite 

 as satisfactory in sujDport of these views as if they were 

 Silurian or older. The finding of fossils in the Morte Slates only 

 added strength to my view, since every species hitherto found is 

 unlike any which are known to occur in the Ilfracombe beds on the 

 north side and the Pilton beds on the south, and yet there are 

 numerous fossils in common in the Ilfracombe and the Pilton beds. 

 This at once proves that the Morte beds and those surrounding them 

 must belong to very different geological horizons. I may say in 

 passing that I took pains, knowing the imperfect material with 

 which I had to deal, to obtain the opinions of several specialists in 

 regard to the fossils before I ventured to publish the conclusions at 

 which I had arrived. Now the fossil which has been mainly 

 attacked by Dr. Gregory is Strichlandinia lirata,^ and his remarks 

 on the other fossils show that they are principally made to back up 

 his contention with regard to this form. I will, therefore, confine my 

 remarks at present almost entirely to the evidence adduced by him to 

 show that our S. lirata is not that fossil, but Bipparionyx proximus, 

 Vanux. His remarks are : " If I had to give [Dr. Hicks' fossil] a name, 

 I should, without much hesitation, call it Hipparionijx aff". proximus, 

 Vanux., and regard it as also closely allied to Orthis Mpparionyx, 

 Dav. non Hall." This fossil was first described in America from the 

 Oriskany Sandstone, and is considered one of its most characteristic 

 fossils. Now the American geologists class the Oriskany Sandstone 

 in the Silurian, but some European geologists place it at the base of 

 the Devonian. In this country the fossil has been found in beds at 



' In my description of Stricldandinia lirata, from the Morte Slates, I stated that 

 it "approaches most closely in its, size and ornamentation the specimens in the 

 Society's Museum and in the Jermyn Street Museum, from the lowest beds of 

 "Wenlock ag-e at Marloes Bay, Pembrokeshire." Last year I visited Marloes Bay, 

 and collected several other fossils from these beds, and I am more than ever convinced 

 that the fauna is the same as that I have described from the Morte Slates. A figure 

 of 8. lirata from Marloes Bay is given on plate xxii in the ' ' Silurian System ' ' 

 (1839) as Spirifer? liratus, afterwards altered to Striek. lirata. After examining 

 the sj)ecimeu figured in the " Silurian System," I am satisfied that it belongs to the 

 same species as ours. It is important to note this, as it was the first' specimen 

 figured, and it is generally recognized as the tj-pe- specimen for the genus 

 Stricklandinia. 



